Net and method of producing same

Abstract

The invention relates to a net composed of a regular array of longitudinal ribbon-formed continuous filaments of a polymer substance, and a regular array of transverse stems of different polymer matter, said filaments being embedded in said stems, as well as to a process of producing such net from a sheet consisting of a regular array of longitudinal ribbon-like polymer filaments embedded in a polymer matrix, the filament polymer having a higher melting point than the matrix polymer, by transversely impressing said sheet at a temperature where siad matrix is at least semi-molten and the filaments are solid, then splitting the structure.

We claim: 
     
       1. A net composed of (a) a substantially equispaced parallel array of distinct longitudinal flat ribbon-like continuous filaments of a first polymeric material, and (b) a substantially equispaced parallel array of distinct individual transverse strands of at least one second polymeric material having a melting point lower than said first polymeric material disposed in crossing relation to said longitudinal filaments and defining zones of intersection between the respective filaments and strands of said two arrays, said filaments extending bodily through transverse strands in said zones of intersection with their flat faces generally parallel to the plane of the net so that a section of each longitudinal filament at each such zone is entirely embedded within said second polymeric material, said distinct transverse strands being arranged in said array in a predetermined generally uniform relationship relative to said continuous filaments and to each other with a generally uniform separation between adjacent pairs thereof. 
     
     
       2. An embossed film product in the form of a net composed of (a) a regular array of longitudinal ribbon-like continuous filaments of a first polymer material; and (b) a regular array of transverse strands of a second polymer material different from said first polymer material disposed in crossing relation to said longitudinal filaments and defining zones of intersection between the respective filaments and strands of said two arrays, said filaments extending bodily through said transverse strands in said zones of intersection so that a section of each longitudinal filament at each such zone is entirely embedded within said second polymer material, said second polymer material having a melting point different from the melting point of said first polymer material, said net being formed by impressing a film product and thereafter cross-stretching of said impressed film product. 
     
     
       3. A net according to claim 2 in which the first polymer material forming the filaments has a melting range higher than the second polymer material forming the strands. 
     
     
       4. A net according to claim 2 in which said ribbon-like filaments are tapered at their edges. 
     
     
       5. A net according to claim 2 in which first and second polymer materials are mutually incompatible at their contacting surfaces whereby said filaments are embedded in slipping relation with respect to said strands. 
     
     
       6. A net according to claim 2 in which said first polymer material forming said filaments are oriented. 
     
     
       7. A net according to claim 2 in which said second polymer material forming said strands are oriented. 
     
     
       8. A net according to claim 2 wherein said strands have integral extensions projecting laterally therefrom at each intersecting zone in enveloping relation around adjacent sections of said filaments to lengthen the extent of embeddment of said filaments in said second polymer material. 
     
     
       9. A net according to claim 8 wherein said lateral extensions from adjacent pairs of said strands are generally continuous whereby said filaments are embedded within said second polymer material over substantially the entirety of their length. 
     
     
       10. A net according to claim 2 in which each of said strands if formed of plural layers of different polymer materials. 
     
     
       11. A net according to claim 10 in which at least one surface layer of each such strand is formed of an olefin copolymer adapted to adhesively bond with cellulose, or of an ionomer, while a further layer of such strand is formed of essentially olefin homopolymer. 
     
     
       12. A net according to claim 10 in which said layers are in a state of differential shrinkage forming a curling of the strand. 
     
     
       13. A net according to claim 2 in which said filaments are formed of a polyamide or of polyethyleneterephthalate, and said strands are formed of polyolefin. 
     
     
       14. A net according to claim 2 in which said strands are of generally circular to squared shape. 
     
     
       15. A net according to claim 2 in which said strands are of generally flat ribbon-like shape.